Many syntheses of drugs and biologically active natural products utilize catalytic cross-coupling reactions as a key step. Cross-coupling reactions often require toxic, expensive, or highly basic reagents to effect formation of organometallic reaction intermediates via transmetalation. The theme of this proposal is the replacement of these undesirable reagents with ubiquitous carboxylic acids. Decarboxylative metalation of carboxylic acid derivatives potentially allows formation of useful organometallic intermediates under mild conditions and produces only non-toxic CO2 as a byproduct. Decarboxylative metalation is being applied to more efficient syntheses of medium- and large-ring ketones, homoallylic amines, functionally differentiated hexadienes, and various biologically important heterocycles including pyridines, azetidines, and piperidines. We have strong preliminary data that demonstrates that enolate, acetylide, amide, allyl, a-amino, and stabilized alkyl nucleophiles can be generated by catalytic decarboxylation of the corresponding carboxylates. We propose to develop synthetic methods based on decarboxylative metalation with a focus on activity, scope, and enantioselectivity. The classes of molecules being targeted for synthetic development have been chosen based on their synthetic flexibility or occurrence as common motifs in natural products and/or Pharmaceuticals. Thus, adaptation of the new strategies developed as a result of this proposal will ultimately contribute to the generation of novel therapeutic reagents to treat human disease.